Tag Archives: vitamin C

‘Tis the season for coughing, sneezing and sniffling. Many of us have stocked our medicine cabinets with vitamins, minerals and herbal remedies to ward off or cure these nasty symptoms of the common cold. Zinc supplements are a particularly frequent treatment, because zinc is known to support immune function. But do zinc supplements actually work?

Zinc is thought to halt the replication of rhinoviruses, the most common cause of colds. A recent scientific analysis pooled data from previous studies that compared oral zinc treatments with placebo or no intervention. It was found that zinc had no significant effect on the severity of symptoms experienced, but zinc did shorten the duration of a cold by an average of 2.63 days in adults. Not all zinc formulations are equally effective, however. Only zinc acetate caused a statistically significant reduction in symptom duration. Zinc gluconate and zinc sulfate were not successful.

So if zinc can help kick a cold faster, how much should we take once we feel the beginnings of a sore throat and runny nose? The evidence says to start using zinc within one to two days after the onset of a cold, but researchers have yet to offer an optimal dose. In the analysis mentioned above, subjects took zinc acetate lozenges every 2-3 hours while awake until symptoms resolved. By my own estimations, this provided about 54-104 mg zinc daily.

Remember that more is not always better. Zinc lozenges may cause a bad taste in your mouth or even nausea. Taking too many, or popping mega-dose zinc tablets can be harmful. The safe upper limit of zinc is set at 40 mg daily. Exceeding this amount for an extended period of time can actually decrease immunity and cause low copper levels.

The bottom line? Zinc may help your body fight the common cold, but if you’re going to load up, do it for a maximum of 7-10 days and be wary of how much zinc you’re ingesting! Read labels and choose supplements or lozenges with zinc acetate (or zincum aceticum) as the main ingredient.

A: Antioxidants are compounds that offset damage to the body’s cells. Antioxidants, including certain vitamins, minerals and phytochemicals, defend against injuries caused by free radicals. But what’s a free radical? Simply, free radicals are oxygen molecules floating around in your system that contain an unpaired electric charge. This single “electron” looks for a buddy to gain stability and so it destructively steals a second electron from substances like cell membranes and DNA. Free radicals form naturally during the metabolism of food, but are also caused by cigarette smoke, air pollution and UV sun rays. While there are some benefits to free radicals, these highly reactive, unstable molecules are implicated in aging, neurodegenerative diseases and cancer. Fortunately, antioxidants can destroy free radicals, limit their formation and stimulate repair activity at the site of damage.

Antioxidant

Food sources

Recommended Daily Amount

Vitamin C

Orange, grapefruit, mango, strawberries, broccoli

90 mg for men75 mg for women

Vitamin E

Wheat germ oil, sunflower seeds, peanut butter

15 mg

Beta-carotene (Vitamin A precursor)

Carrots, sweet potatoes, broccoli

None established

Selenium

Brazil nuts, tuna, turkey, rice

55 µg

Lycopene

Tomatoes, ketchup, watermelon

None established

Lutein

Dark, leafy greens (e.g. spinach)

None established

Resveratrol

Red grapes

None established

Anthocyanin

Blueberries, raspberries, plums, red grapes

None established

There is no set daily recommendation for most antioxidants; however, eating more fruits and vegetables is the best way to boost your intake. Rely on whole foods, not supplements, since popping high dose capsules can have negative health effects. For example, beta-carotene supplements are associated with higher rates of lung cancer in men; however, smokers are recommended to increase vitamin C intake, due to smoke-induced oxidative damage. My take? Get your antioxidants from food sources, steer clear of mega-dose pills and stick to recommended daily amounts of vitamins & minerals.